Years ended December 31,

2019

2020

2021

(In thousands)

Accumulated other comprehensive loss, net of tax:

Currency translation:

Balance at beginning of period

$

(172,434)

$

(172,843)

$

(169,575)

Other comprehensive income (loss)

(409)

3,268

(1,660)

Balance at end of period

$

(172,843)

$

(169,575)

$

(171,235)

Defined benefit pension plans:

Balance at beginning of period

$

(75,286)

$

(78,257)

$

(80,704)

Other comprehensive income (loss):

Amortization of prior service cost and net losses included in net
periodic pension cost

3,539

4,330

4,813

Net actuarial gain (loss) arising during the year

(6,510)

(6,777)

7,423

Balance at end of period

$

(78,257)

$

(80,704)

$

(68,468)

OPEB plans:

Balance at beginning of period

$

(550)

$

(590)

$

(910)

Other comprehensive loss - amortization of net
gains included in net periodic OPEB cost

(40)

(320)

(143)

Balance at end of period

$

(590)

$

(910)

$

(1,053)

Total accumulated other comprehensive loss:

Balance at beginning of period

$

(248,270)

$

(251,690)

$

(251,189)

Other comprehensive income (loss)

(3,420)

501

10,433

Balance at end of period

$

(251,690)

$

(251,189)

$

(240,756)